Please contact NGDC's water column sonar data staff () if you have questions.

Water Column Sonar Data

NOAA collects and uses active acoustic (or sonar) data for a variety of mapping requirements. As the national
archive for multibeam bathymetric data, NGDC manages over 15 million nautical miles of ship trackline data
from sources worldwide. In 2011, NGDC, in partnership with NOAA's National Marine Fisheries Service (NMFS), initiated a new archive for high resolution data collected with sonars
capable of mapping the water column.

Water column sonar data are collected on NOAA fishery survey vessels and academic and international
fleets, and are used to assess the physical and biological characteristics of the ocean. Primary uses include
3-D mapping of fish schools and other mid-water marine organisms, assessing biological abundance, species
identification, and habitat characterization. These data are also useful for evaluating underwater gas seeps,
remotely monitoring undersea oil spills, and bathymetry.

NGDC is working with scientists at NMFS and the Joint
Hydrographic Center to ensure the long-term preservation and world-wide dissemination of these data.

The main focus of these efforts is to create an accessible national archive of water column sonar data and to
assist NMFS in meeting their data management and accessibility requirements.

Figure 1.Water column sonar data collected on the NOAA Okeanos Explorer in July 2013
within the North Atlantic Ocean. The sonar data are overlaid onto coastal relief model
bathymetry courtesy of Elliot Lim.The backscattered signal (green) above the bottom is likely
the deep scattering layer. (top) A movie capturing the time lapse of one data file and
(bottom) a static image of the near-nadir beam curtain of that same file.

Accessing and Archiving Data

These data can be accessed and requested through the interactive map at left. Data are available for free and without copyright restriction, and can be selected and requested through the viewer above, but may require the requestor to provide an external hard drive.

Please contact NGDC's water column sonar data staff () if you have questions concerning these data or new water column sonar data
you are interested in archiving for public access. When submitting data, you will be asked to provide metadata
for each survey.